Spokesmen for the industry have unanimously dismissed claims that a tax would help Britain lose weight.

An industry body has said their products account for just 2% of calories in an average diet and it is what people consume overall which needs to be addressed.

Soft drinks manufacturers have argued an extra tax will not combat obesity

They also said sales of fizzy drinks have fallen during the last decade, but levels of obesity have risen.

Gavin Partington, director-general of the British Soft Drinks Association, said: "We share the recognition that obesity is a major public health priority but reject the idea that a tax on soft drinks, which contribute just 2% of the total calories in the average diet, is going to address a problem which is about overall diet and levels of activity.

"Over the last 10 years, the consumption of soft drinks containing added sugar has fallen by 9% while the incidence of obesity has been increasing, and 61% of soft drinks now contain no added sugar.

"Soft drinks companies are also committing to further, voluntary action as part of the Government's Responsibility Deal Calorie Reduction Pledge.

"Don't forget that there already is a 20% tax on soft drinks, 10p out of every 60p can of drink already goes to the Government thanks to VAT.

"Putting up taxes even further will put pressure on people's purses at a time when they can ill afford it."

The AMRC, which represents nearly every one of Britain's 220,000 doctors, is pressing the Government, the NHS and food organisations for action on what it calls the greatest public health crisis affecting the UK, the Guardian said.

Figures say one in four adults is obese and that number is expected to double by 2050, presenting an unresolvable problem.

The report says doctors from across the medical profession are united in their concerns, and criticised the present and previous governments for insufficient and ineffective attempts to tackle the problem.

Following a year-long inquiry, the AMRC has devised a list of 10 recommendations to stop the UK being the fat man of Europe.

These include taxes of 20% on sugary drinks for at least a year, banning the advertising of foods high in saturated fat, sugar and salt before 9pm, and councils having the power to limit the number of fast-food outlets near schools and leisure centres.

They also include advice for new parents on how to feed their children properly, NHS staff to talk to overweight patients at every appointment about their eating and exercise habits, and more surgery for the severely obese, to help those at risk of dying.

Professor Terence Stephenson, the chairman of the AMRC, told the Guardian the report is not a full solution to obesity, but attacked fizzy drinks, saying a tax on them is justified as they are the ultimate bad food.

And he told the BBC that while there is no silver bullet for tackling obesity, the eating culture needs to be changed to make it easier for people to make healthy decisions.

"I choose what I eat or whether I smoke. What people have told us is they want help to swim with the tide rather than against the current to make the healthy choice the easy one," he said.

"Doctors are often accused of playing the nanny state. We didn't hear from a single person who said they liked being overweight - everybody we met wanted help from the state and society.

"If we didn't have things like this we wouldn't have speed limits that save lives, we wouldn't have drink-driving limits that save lives.

"There's a host of things that society and state does to help us live long, healthy, fulfilling lives and we're just suggesting something similar."

But the Food and Drink Federation (FDF), which represents manufacturers, also dismissed the report, saying it added little to an important debate.

Terry Jones, from the FDF, told the BBC: "The Academy of Medical Royal Colleges has presented as its recommendations a collection of unbalanced ideas apparently heavily influenced by single-issue pressure groups.

"FDF had hoped that today's report would have looked seriously at how the food industry and the medical profession would have worked together to tackle obesity, and genuinely brought new insights to bear on how to empower healthier choices and change behaviour to deliver better long-term public health outcomes.
"This report fails to do that."

The Department of Health (DoH) acknowledged that the threat posed by obesity in both adults and children is one of today's most important public health challenges.

A DoH spokesman said: "This wide-ranging report from the Academy of Medical Royal Colleges recognises, as did our own recent Call To Action On Obesity, that there is no single answer to the obesity problem.

"It is up to everyone - Government, industry, health professionals and voluntary groups, as well as individuals themselves - to work jointly to promote healthy eating and healthy lifestyles."